Effectiveness of Three Prognostic Scoring Systems in Predicting the Response and Outcome in Pediatric Chronic Myeloid Leukemia Chronic Phase on Frontline Imatinib.

Introduction: The Sokal and Hasford (Euro) scores were developed in the chemotherapy and interferon eras and are widely used as prognostic indicators in patients with chronic myeloid leukemia (CML). Recently, European Treatment and Outcome Study (EUTOS) scoring system was introduced. Data on risk stratification in pediatric CML population was lacking due to its rarity (<3%).

Objective: To study the effectiveness in predicting the response and outcome with three prognostic scores in pediatric CML-chronic phase patients on front line Imatinib. Materials and Methods: We retrospectively analyzed the hospital records of newly diagnosed CML CP patients (aged ≤18 years) from 2006 to 2010 for their risk score, cytogenetic response at 18 months and event free survival (EFS) at the end of 4 years. Events include loss of hematological response, loss of cytological response, progression to accelerated/blast phase (AP/BC). All received free Imatinib under Gleevac international patient assistance program.

Results: Data of 106 children was analyzed with median age of 13.5 (ranged 5-18 years) and male preponderance (M:F = 1.14:1). The distribution of children was 63%, 32% and 5% in Sokal low, intermediate and high risk respectively, 50%, 43% and 5% in Hasford/Euro low, intermediate and high risk respectively, 71% and 29% in EUTOS low and high risk respectively. The overall cumulative complete hematological response at the end of 3 month was 94%, and complete cytogenetic response at 12 months was 75%. The CCyR at 18 month was seen in 90%,74% and 83% among Sokal low, intermediate and high risk groups respectively, 83%, 86% and 83% among Hasford/Euro low, intermediate and high risk groups respectively, 84% and 86% EUTOS low and high risk groups respectively. The EFS at the end of 48 months was seen in 87%,79% and 83% among Sokal low, intermediate and high risk groups respectively, 83%, 86% and 83% among Hasford/Euro low, intermediate and high risk groups respectively, 86% and 80% EUTOS low and high risk groups respectively.

Conclusion: None of the scoring systems predicted the response and outcome effectively in children with CML CP on front line Imatinib.